Apparatus for the manufacture of tubes of



June 25, 1929. D. MATTE! ET AL APPARATUS FOR THE MANUFACTURE OF TUBES 0F CEMENT ASBESTOS ,OR SIMILAR SUBSTANCES 4 Sheets-Sheet INVENTORS gr mm 1' Wk whiny 3 .4 TTORALJ'S Original Filed Feb. l8. 1921 J1me 1929- D. MATTE! ET AL Re. 17,335

APPARATUS FOR THE MANUFACTURE OF TUBES OF CEMENT ASBESTOS OR SIMILAR SUBSTANCES Original Filed Feb. 18. 1921 4 Sheets-Sheet 2 INVENTQRS .}VTTORNEY9 June 25, 1929. D. MATTE! ET AL Re. 17,335

APPARATUS FOR THE MANUFACTURE OF TUBES OF CEMENT ASBESTOSTJR SIMILAR SUBSTANCES Original Filed Feb. 18. 1921 4 Sheets- 'lheet. 5

l 11v VENTOk s ATTORNEYS June 25, 1929. n. MATTEI ET AL APPARATUS FOR-THE MANUFACTURE OF TUBES OF CEMENT ASBESTOS OR SIMILAR SUBSTANCES Original Filed Feb. 18'. 19 4 Sheets-Sheet 4 I Reissuecl June 25, 1929.

UNITED STATES- Re. 11,335 PATENT OFFICE.

DIEGO MATTEI AND ADOLFO MAZZA, 'Oli GENOA, ITALY, ASSIGNORS TO ETERNIT PIETRA ARTIFICIALE, SOGIETA ANON MA, OF GEN'OA, ITALY, AN ITALIAN COM-.

IPANY.

APPARATUS FOR THE -MANUFAGTURE OF TUBES OF CEMENT ASBESTOS OR SIMILAR SUBSTANCES.

Original No. 1,627,104, dated. May 3, 1927, Serial No. 446,046, filed February 18, 1921, and in Italy March- 2, 1920. Application for reissue filed April 22, 1929. Serial No. 357,256.

The manufacturing of cement-asbestos tubes (Eternit tubes) or of tubes of similar substances for high pressure piping with the so called revolving, machines employed in the manufacture of cardboards, though on first sight it may appear a simple matter becauseEternit slabs in fact are but tubes out along one of their generating lines and then developed on a flat surface while they are still in soft conditions, yet in practice involves numerous di fliculties of various kinds on account of the various requirements which theltubes must fulfil.

These requirements may be summarized as follows:

1st. The tubes should be perfectly'eircular in cross section and their inside diameter should'be uniform. v

2nd. They should exhibit a uniformthickness and a high strength in orderto be capable to withstand the high pressures to which they willbe subjected;

3rd. They should be 3 to 4 metres long, that I is to say much in excess of the ordinary width (1,20 metres) of .the'machines for the manufacture of Etcrnit or cement and asbestos slabs.

4th. They must be evenly compressed over their whole length in order that they may be possessed of equalstrength throughout.

With Eternit machines (suitably widened to give the required tube length) in which the pressure on the tube making cylinder is applied at the end of the cylinder axis, even if this pressure, by means of sleeves, be transmitted to the inside of the cylinder at the points that are most convenient towards the reduction of sagging, yet it is absolutely impossible to obtain pipes of small or medium size and considerable thickness complying with the above said requirements for two reasons: firstly because, due to the rolling acto forces arising in vertical direction owing tion on the material, the material detaches itself from the main cylinder or mandrel especially in, the center portion, thus increasing in diameter before it has reached the required thickness, and in the second place because the pressure; especially with smaller pipes, cannot be evenly distributed over the whole length on accountpf the sagging that occurs in the main cylinder or mandrel due to the manner in which pressure is'applied and in horizontal direction from the tangential action of the travelling'band.

The rolling actionis due not only to the pressure exerted on the material along the generating contact line between the main cylinder or mandrel and the band-carrying cylinder, but also to the tangential action exerted on the material in order to make the main cylinder revolve and to overcome the passive resistances.

The passive resistances mainly consist in the friction set up in the main cylinder bearings and due to the vertical pressureto which the bearings are subjected and to the horizon tal pressure exerted b the travelling band. The stresses to which t e pipe-material is subjected due to these resistances will obviously increase with decreasing pipe diameter, and

with small pipes will be still greater because sagging cylinders must be rotated.

In order to remove or lessen the said inconveniences it will be necessary 1st. To arrange that the material be tenacious as much as possible consistently with the other requirements of the working process, and consequently that it be compressed and liberated from the excess water before it.

small aspossible, to eliminate or minimize the bearing friction and to increase the pipe surface portion over whichthe force required to rotate the main cylinder and the pipe is ap-' plied.

A greater compactness of the material can be obtained by the use of one or several pairs of pressure rollers arranged between the ordi nary water suction and the main" c linder. The top roller in the said pairs should e more or less loaded by means of weighted levers according as may be required. It must be pro.- tected against the material sticking to its surface by means of an endless felt belt provided with suitable guiding, washing, squeezforinstance,enveloping as much as possible of the pipe surface and simultaneously subjected to tension; or, next to the said method,

to subject the pipe to the action of a set of' rollers that are positively driven but not loaded at their ends, these rollers being distributed over the pipes periphery and weighting thereon with all their weight and being capable of being shifted along straight or curved guides according as the pipe increases in thickness, or by suitably combining a driven flexible organ and a set of rollers as above indicated, in

which case the flexible organ, beside preventing the material from sticking to the rollers, fulfils the duty of preventing the pipe from detaching itself from the main cylinder between two successive rollers.

I In ordinary cases, that is to say for the most current pipe diameters, a single couple of heavy rollers will suflice, the two rollers being symmetrically arranged with respect to the vertical line perpendicular to the generating contact line between the pipe and the felt band supporting roller and being driven by an endless felt band which embraces a larger or smaller portion ofthe pipe periphery, the embraced portion being greater according as the pipe'diameterand thickness are greater; such an arrangement will'suflice to obtain the de sired pipe thickness. N

In order to effect the required pressure variations, the two pressure rollers should bear upon'the pipe as already stated and in addition to this their journals should rest on two convenientlyshaped surfaces and be capable lower'felt bandfsupporting roller will be the of freely sliding along the same while the pipe is being built and increases in thickness.

The pressure exerted by each roller upon the a pipe in each successive position will be ob tained by splitting their weight into two components, viz, one normal to the resting surface and the other, which is the useful component, normal to the pipe, that is to say along the centre line of the pressure roller and of the pipe. The totallpressure exerted on the generatingcontaet line between the pipe and the resultant of the two, part pressures.

If the shifting'of the pressure rollers is ef fected on plane surfaces so that the center line always maintains the same inclination, the pressure on they pipe will remain constant.

In-order to vary the pressure the direction i of the perpendicular to the resting surface must be varied and in such a case, if the-said perpendicular is horizontal, the pressure on main cylinder before it has reached the desired thickness.

The felt band interposed bet-weenthe pressure rollers and the pipe and embracing a portion of the pipe periphery as said above further prevents the pipe material from adhering to the rollers and must accordingly be,

not only driven, but also guided, Washed and squeezed.

The described arrangement also exhibits the advantage that it does away with or appreciably reduces the passive resistances already spoken of. The pressure on the main cylinders being no longer applied to their journals, the friction resistances in the bearings due to vertical actions no longer subsist. The tangential action of the mainfelt band being neutralized or lessenedby that of the felt band driving the pressure rollers and running in opposite direction ..alsothe resistances due to tangential forces will be nearly altogether eliminated. The bearings which in ordinary machines hold the main cylinders in place can therefore be dispensed with and replaced by mere guides serving to ensure the vertical raising of the main cylinder while the pipe is be ing formed.

Oneembodiment of the invention is illustrated in the annexed drawings by way of example.

Fig. 1 diagrammatically shows the whole machine in sideview.

Fig. 2 shows in s1de view and to a larger scale the detailof the pressure rollers and how they are mounted.

Fig. 3 is a section through AB-C D in Fig. 1 and shows how the pressure rollers are supported.

Figures4 and 5 area view and a section respectively of-a curved guide for the pressure roller journals. I

Fig. 6 is a view of a double curved guide.

Fig. 7 is a View of a double straight guide.

' Fig. 8 shows a modified arrangement of the guides, mam cylinder and pressure rollers speciallyadap'ted for pipes possessing a large diameter and a large thickness.

Figures 9 and 9 are diagrams showing how the pressure distributes itself over the pipe according to the various thicknesses which the pipe is successively acquiring.

The machine comprises firstly a certain.

number of parts which it has in common with the ordinary cardboard and Flternit machines v1z,: vats 1 contalnmg the mixture,

travelling endless felt band 3; the pressure,

rollers & assisting in the delivery of the mixture from the rollers 2 onto the felt band;

band guiding. rollers 5, take-up rollers 6, adjustable rollers 7 for holding the bandin the center, exhauster 8 taking out the lllOlStLllG from the mixture carried on the band, band striker '9, perforated tubes 10 washing the band, squeezing rollers 11 for squeezing the water out of the band after washing, main band-supporting roller 12 (base roll) on which rests the main pipe forming cylinder or mandrel 20.

The following parts complete the machine:

A couple of squeezing rollers 13 13, for further drying the mixture so as to give it a suitable consistency to which object the upper roller may beweighted down on the lower roller by means of weighted levers so as to exert greater or smaller pressure according as may be required: a travelling endless band 14 winding itself round the upper roller 13 in order to prevent the mixture sticking to this roller; a guiding roller 15 and'a'takc-up roller 16 forthe band 14:, an adjustable roller 16 for holding the band 14: in the middle, the washing tubes 17 and the driven squeezing rollers 18, and the vat 19 receiving the wash water.

20 is the main cylinder or mandrel on which i the pipe is formed, and" 21 21 the pipe compressing rollers (press rolls) carried by jour- 22 22 are the slotted guides in which the journals 21 21 are carried and can freely move. 23 (Fig. 3) are the pivots of the guides 22 and are inserted in the supports 24; by means of a handwheel and of the right and left hand threaded screw 25 the two supports 24 may be moved further apart or nearer to each other, whereby also the pressure rollers, 21 21 are brought farther apart or nearer to each 0tl1er;26 is a T-shaped piece carrying the screw 25, and 27 is a vertical guide inside which the main cylinder 20 or its journals maybe moved up and down while the pipe is building. 28 are guides secured to the uprights of the machine framework; the T-shaped piece can move vertically along these guides. 29 is a rod on which the T- shaped piece 26 is suspended, the rod29 being'actuated by a piston 30 working in a cylin'der31.

By means of a pressure liquid fed into the cylinder 31 the whole movable equipment comprising: piston, piston rod 29, T-shaped piece 26, slotted guides 22 and pressure rollers 21 can be raised or lowered to the object of enabling the main cylinder 20 to be used 'to manufacture pipes of any diameter and of extracting the pipes after completion.

32 is a travelling endless band passing between the pressure rollers21' 21 and the pipe ranged to move in vertical slots; this and encircling a portion of their periphery. 33 are guiding rollers for the said band; 34: are washing tubes; 35 are the driving and at the same time the squeezing rollers for the said band. 36 are adjustable rollers for keeping the band 32 inthe middle, 37" is a heavy take-up roller for the said band and is freely carried on levers 38 or it may be arroller keeps the band duly taut when the movable equipment is raised, as shown by thedotted line 32, and permits the pressure rollers 21 21 to be raised during the manufacture of the pipes. 39 is a stop' against which the ,1 T- shaped piece bcars during the building of the pipe.

The guides 22 can be differently inclined v by operating thescrow 40 which actuates the links 41 attached to lugs projecting from the said guides (Figures 2 and 3). In this way the distribution of the prcssureexerted ohthe" pipe by the rollers 21 can be varied.

The guides 22 may. also be locked'inany desired inclination by means of the set-screw 42 (Figures 4 and 5) fitted to the blocks24 and working upon the pivots 23. The guiding slots. may be curved (Figures 4, 5 and 6) or straight (Fig. 7 and may be formed inthe" T-shaped piece 26 itself instead of in a sepa According to the arrangement illustrated rate piece secured thereto.

in Fig. 8 (which enables the band to embrace a larger portion of the pipe periphery than the previous arrangement, as may be desirable when larger and thicker tubes are who manufactured) 50 is the main cylinder, 51 the pres sure cylinders in their initial position viz. A

when they rest directly on 50, whereas 50' and .51 respectively show the pipe when it has already attained a certa inthickness and the pressure cyhnd ers in their new corresponding position.

From the Figures 9 and 9 it readily appears that the pressure exerted by the pressure rollers is gradually reduced according as the pipe increases in thickness.

Let OPO'P'O"P" be the weight of mg surface in the successive positions 32 is the travelling endless felt band embracing a portion of the pressure rollers and a considerable portion of the pipe,

llU

weight components along thelines connecting a the center of themain cylinder: and of the pressure cylinder, that is to say the pressures corresponding to the three positions OO O of the pressure c vl inders. I The worklng of the machine is as, follows:

After raising the movable equipment the mam cylinder 20 1s made to rest on the main 7 tubular bodies, the cylindrical mandrel, rolls encompassing and pressing upon said band-s upportin g roller 12. The movable proper position. The movable equipment is then locked against the stop 39.

The machine is now set running and the pressure rollers rise along their respective guides according as the pipe thickness increases. hen the pipe is completed, the movable equipment is raised in order to allow of the pipe being extracted.

Having described our invention, what we claim, and desire to secure by Letters Patent 15:

1. In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel, a plurality of forming rolls encompassing and pressing upon said mandrel, means for supplying a web of cement and fibre mixture tothe mandrel, and

means for gradually reducing the pressure upon the mandrel as the of the forming rolls body builds up on the size of the tubular mandrel. I 2. In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel, a rolls between which the mand el is located in operation, said forming rolfs comprising a base roll and a press roll, and means for gradually reducing the pressure of the press roll upon the mandrel as the size of the tubular body builds up on the mandrel.

3. In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel, a plurality of forming rolls between which the mandrel is located in operation, said forming rolls comprising a base roll and two spaced press rolls, and means for gradually reducing the pressure of the press .rolls upon the mandrel as the size of the tubular body builds up on the mandrel.

. 4. In a machinefor making cement fibre combination of a rotary a plurality of forming mandrel, means for supplying a web of icement and fibre-mixture to the mandrel, and guiding means for one of said forming rolls to permit its displacement under the action of building upa tubular body upon the mandrel, and for gradually reducing the pressure of the displaced forming roll upon the mandrel as the thickness 0 thetubular body is increased.

5. In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel, a plurality of forming rollsbetween which the mandrel is located in operation, said .forming rollscomprising a base roll and a. press roll, and guiding means for'said press "rolls to permit its displacement and gradually reduce the pressure of the press roll upon the mandrel as plurality of forming.

passed in operation, said forming rolls 'comprising a base roll and two spaced press rolls, and guiding means for said press rolls to permit their displacement and gradually reduce their pressure. uponthe mandrel as the size of the tubular body builds up on the mandrel. a

7. In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel,'a lurality of formin rolls encompassing an pressing upon said mandrel, means for supplying a Web of cement and fibre' mixture to the mandrel, a flexible band or apron partially encircling said mandrel and means :for gradually reducing the pressure of the forming rolls u on the mandrel as the sizeof the tubular body builds up on the mandrel.

8. In a machine for making cement fibre tubular bodies, the combination of arotary cylindrical mandrel, a plurality of forming rolls between which the mandrel is located 1n operatiomsaid forming rolls comprising a base roll and two spaced press rolls, a flexible band or apron running between the mandrel and the press rolls and partially encircling the mandrel, and means for grad ually reducing the pressure of the press rolls upon the. mandrel as the size of the tubular body buildsup on the mandrel.

9, In a machine for making cement fibre tubular bodies, the combination of a rotary cylindrical mandrel, a plurality of forming rolls between" which the mandrel is located in operation, said forming rolls comprisin' a base roll and a press roll, guides for saic press roll to permit its displacement and gradually-reduce its pressure upon the tubular body as it builds up ontthe mandrel, and

means for adjusting said press roll guides to form tubular bodies of different diameters.

.10. In a machine for making cement fibre f the combination of a rotarytubular bodies, cylindrical mandrel, a plurality of forming rolls between which the mandrel is located in operation,

said forming rolls comprising a base roll and two spaced press rolls, movpress rolls upon the mandrel as the size of the tubular body builds up on the mandrel, and adjustable means controlling the position of said guide members.

11. In a machine for the manufacture of pipes of the character described, means for forming a pulp layer. comprising a pair of squeezing rollers, an endless band for protecting from the pulp the upper roller of said pair, a main pipe formin cylinder for receiving the layer of pulp, a ter the latter has passed between said squeezing rollers, a

flexible band partially encirclin the periphery of the pipe forming cy inder for compressing the pulp thereon, a set of heavy driven rollers distributed along the periphcry of the pipe forming cylinder to compress the pulp during the manufacture of the pipe, and means for guiding the latter rollers to permit their displacement and for pipe from detaching itself 'from the main cylinder between the rollers, and reventing the pulp from sticking to the re lers.

13. A machine according to claim 11, having carrying means for the said heavy driven rollers and their guiding means, fluid pressure mechanism for moving the said carrying means into and out of the operative position during the manufacture of the tube, and

.a take-up roller device for tightening the flexible band as the carrying means is moved.

7 14. A machine according to claim 11, having means for adjusting said roller guiding and pressure-reducing means to form pipes of difiere'nt diameters.

. DIEGO MATTEL ADOLFO MAZZA. 

